Model output discussion - 7th January onwards

[karlos1983]

My mood is lifted! Thanks GFS always believed In you

that would be the ultimate end game & I wanna play!

Edited January 12, 2019 by karlos1983

[Snow Grain]

5 minutes ago, Ed Stone said:

Looking good, the micro-details hardly matter - defo cold slider-potential - snow's a-comin!

  

Unfortunately that’s low ground rain.  Only snow on high ground over northern hills.

[IDO]

Nice end to GFS op and shows the potential once the Canadian vortex discharges:

[bluearmy]

According to the eps clusters - the op fits this ??????

 

 

 

Edited January 12, 2019 by bluearmy

[Methuselah]

The build blocks are in place...generally cold but with possible short-lived wetter, milder interludes?

 

[feb1991blizzard]

1 minute ago, bluearmy said:

According to the eps clusters - the op fits this ??????

 

 

That's why i am not a fan of the way clusters are generated, it will always be liable to computers only having artificial intelligence, i would rather actually have the mean of each cluster, rather than 1 single member representing it, that would iron out those situations.

[Shunter]

23 minutes ago, nick sussex said:

You have to question what’s going on! I mean the differences between this run and the earlier GFS at day ten .

 

Yes it does seem that the GFS super computers cannot resolve the post SSW impact for the North Atlantic. Despite the positive signals all over the Strat & Trop, the reviving PV definitely seems to want to head home to its North American lair. 

[Banbury]

You have to laugh in here , snow for many from next Sunday onwards 

[Man With Beard]

11 minutes ago, bluearmy said:

According to the eps clusters - the op fits this ??????

 

 

Illogical!

But overall the clusters were a good representation of what I saw on the individual members. 

[Ali1977]

There’s no denying the fact that the 850s atleast are down compared to yesterday for next weekend , -6 mean is now -4/-2. 

Edited January 12, 2019 by Ali1977

[bluearmy]

4 minutes ago, Man With Beard said:

Illogical!

But overall the clusters were a good representation of what I saw on the individual members. 

I guess if the op is the only member of 51 showing close to that solution then you either find it a closest fit or otherwise ........ 

[Mike Poole]

4 minutes ago, Man With Beard said:

Illogical!

But overall the clusters were a good representation of what I saw on the individual members. 

Think the purple border is the clue, indicates (I think) Scandi block pattern wider than the area you can see.

[bluearmy]

That gfs is different to the last one, especially in the mid range, but again, it fits general ens guidance and is worthy of debate and consideration as a way the next two weeks will pan out . 

[bluearmy]

2 minutes ago, Mike Poole said:

Think the purple border is the clue, indicates (I think) Scandi block pattern wider than the area you can see.

Reds are high anoms mike  ........

sorry - see what you’re getting at but still doesn’t work, especially in the e Atlantic sector 

Edited January 12, 2019 by bluearmy

[NorthernRab]

GFS 6hz run looks a bit 2009 in the sense that the milder interludes are less pronounced the further north you go - during that spell there was continuous snow for most of Scotland from 18th December until 11th January. It's a risky game but these 'milder' interludes are what's often required for significant snowfall as the Atlantic moisture hits a cold continental air flow. The 6hz is likely a variation on the theme (that is, cold and generally blocked) so I wouldn't lose to much sleep over one run. 

[Mike Poole]

1 minute ago, bluearmy said:

Reds are high anoms mike  ........

No I meant the purple coloured border to the Icelandic chart, BA.

Edited January 12, 2019 by Mike Poole

[bluearmy]

Just now, Mike Poole said:

No I meant the purple border to the Icelandic chart, BA.

I know - we crossed in edits .....

[Tim Bland]

Ops are all over the place but it’s encouraging to see that all roads lead to cold and snow potential by 22nd!

just a reminder that when saving images of charts (on Android or IOS ) all you do is press and hold the image then select save, it will then drop the full image into your photos. That way it’s easy for members to follow which model, date and time you are referring to.

[Man With Beard]

20 minutes ago, feb1991blizzard said:

That's why i am not a fan of the way clusters are generated, it will always be liable to computers only having artificial intelligence, i would rather actually have the mean of each cluster, rather than 1 single member representing it, that would iron out those situations.

It is a bit frustrating that we don't completely get what's happening with the clusters. But we've had some great successes using them haven't we, like predicting the onset of the heatwave back in June. A good tool but with limitations, I think! 

[phil nw.]

GFS 06z is just another variation of the same outlook really.Week 1 is all about the gradual change to a nw/se pattern as opposed to the current mild south westerly flow up and around the high.

Day 5 on this run again shows the first push south of cold 

with snowfall for some.

The thing is this is not is yet a pattern with much amplification hence we look for the sliding lows v little wedges of heights along the the thermal boundary.

Looking beyond day 5 is not much help as this micro detail will change day to day and a 50/100 miles change in the boundary can mean a big difference on who gets any snow with this set up. 

There is still some mobility west to east in the Atlantic over the next 10 days so until this relents the risk remains of some less cold air pushing in but this is what gives us the snow chances as the 2 air masses battle it out.

The picture going into week 2 is still a getting colder one as the jet along with that Scandi.trough digs further south.

ECM Mean T240hrs

so the Arctic cold will continue to bleed south in pulses rather than a dramatic plunge from say a clean Greenland high.

London ens still going cold around day 5 and staying cold so no change on a colder outlook.

[SMU]

The current 06z GFS is disguarded in favour of the UKMO / ICON > NAVGEM blend-

( NAVGEM because it replicates the evolution not because its the NAVGEM )

UKMO & NAVGEM together 144

Pretty similar - UKMO has better blocking to the west-

NAVGEM 180

Very similar to the ICON with deep cold sliding back over the UK - back edge snow & the atlantic trough axis alligned & in prime position for another slider-

[bradymk]

The 06z Para sliding nicely at 180 to the west of us.

[SMU]

FV3 is much better than the 06z - more towards the ECM -

it has the slider scenario but much more acute leaving a very cold surface high to the NE-

186 has a continental feed & -8c over England - which signifies very low maxima ( circa 1-2c )

Just to add for Sat the FV3 at 7pm has the 0c isotherm at sea level

Edited January 12, 2019 by Steve Murr

[Ali1977]

13 minutes ago, bradythemole said:

The 06z Para sliding nicely at 180 to the west of us.

Much better, UK cold from next Thurs on this model. Moisture could fall as snow for many. All up in the air though, STILL no 7 day agreement within the models 

[johnholmes]

1 hour ago, Ice Day said:

Indeed, to prove your point here is the 6z at 234 vs the 0z at 240.  All roads still looking wintery though!!

  

At the risk of becoming a bore.

Why are you or Nick S surprised at successive model runs 234-240h being not the same? Try checking the same run, yesterday with the one today etc.

Honestly you will get a more balanced view of just how the model is developing any particular theme.